1. Field
Methods and apparatuses consistent with exemplary embodiments disclosed herein relate to generating depth images.
2. Description of the Related Art
Recently, research on three-dimensional (3D) cameras, motion sensors, and laser radars (LADARs) capable of obtaining information about distances to certain objects have increased. Particularly, as 3D display apparatuses capable of displaying depth images have been developed and demand therefor has increased, the importance of 3D content has also increased. Therefore, various 3D image generating apparatuses enabling users to create 3D content have been researched.
Depth information regarding distances between surfaces of an object and a 3D image generating apparatus may be obtained by using a stereo vision technique using two cameras or a triangulation technique using structured light and a camera. However, the accuracy of depth information obtained by using such techniques rapidly deteriorates as a distance to an object increases. Also, since these techniques are dependent on the surface conditions of the object, it is difficult to obtain precise depth information.
To overcome such problems, a time-of-flight (TOF) technique has been introduced. In the TOF technique, a light beam is emitted to an object and a time of flight of the light beam reflected by the object and received by a light receiving unit is measured. The TOF technique includes a series of light processing operations for extracting depth information, the operations including emitting a light beam having a particular wavelength (e.g., a near-infrared ray having the wavelength of 850 nm) from an illumination optical system including a light-emitting diode (LED) or a laser diode (LD), receiving, at a light receiver, a reflected light beam that has the same wavelength as the emitted light bean and is reflected by the object, and modulating the received light beam via an optical shutter that has a gain waveform known in the art. Various TOF techniques have being developed based on these light processing operations.